However, when I create a viewport and display the part in the the layout the angular measurement is another. See attachment 2.

In the model it should be noted that the part displayed is a detail copied with a different scale as to Zoom in on a detail in order to put dimensions on it. It was created by copying a part of the model and pasting it back in the model but with 3x zoom.

I have also included the full .dxf file in the hope that it helps you both reproduce and fix this issue

Note: The same problem seems to also produce “ghostlines” in other viewports in the layout which is not present in the model. Removing the angular measurement also removed the ghostline. You can observe the issue by looking at layout2 and you can see a line (dimension layer) going from top right corner of the viewport towards the lower left. This line is not present in the model and appears to be some strange extension to the angular dimension the detail that is just to the top right in the model.

Properly related to this issue:If I modify (Move, Rotate, Mirrow, Flip etc.) parts of a drawing which contains an Angular or Arc Length DIM the result will show that those DIM's were uncontrolled changed.